Bristol-built buses have a reputation the
world over for longevity and reliability. This is partly due to the
quality and care with which they were built and partly due to a reliance
on tried and tested technology. Until the early 'sixties
triple-servo vacuum-assisted mechanical brakes were the norm along with
mechanical transmission utilising a 4 or 5-speed synchromesh gearbox
usually of Bristol's own design.

Buses are often classified as being either
'light' or 'heavy'. The majority of Bristol types fall into the 'heavy'
classification. Although all the Bristol chassis are very similar in
construction, they have generally been designed specifically for the type
of body that they were intended to receive; thus though there was a strong
family resemblance between the K and the L types, the K was specifically a
double-deck chassis, the L a single-deck one. The the typical
Bristol chassis is formed from deep steel pressings a quarter of an inch
thick. Corrosion problems are rare, as is chassis distortion due to
accident damage. As a friend of mine put it, when looking at some
parts removed from my own bus for reconditioning, 'that's GWR engineering,
that is!'. An interesting comment given the association between the
Tilling bus group (to which Bristol belonged) and the main-line railways
in the 1930s.

Bristol did manufacture some light-weight
vehicles, in the 1950s the LS ('light saloon') type, the SC (small
capacity') and in the '60s the SU ('short underfloor') and the LH
('light-weight Horizontal' ), the latter two indicating the position of
their engines in the type code. The SU and the SC departed from
normal Bristol practice in that some running gear was bought in, notably
axles from Bedford and Austin and gearboxes from David Brown.

The railway connection continued in the
1950s when, like all the Tilling transport companies, the Bristol came
under the aegis of the British Transport Commission. This led to the
building of two Bristol/ECW
railbuses which had useful lives on the Scottish Region of British
Railways.

The Lodekka was an innovation for which the
railways were largely responsible; the number of low-clearance
railway bridges that had been constructed during the period in which the
railways were being developed meant that uncomfortable 'low bridge'
double-deck bodies had been constructed with an upper deck with four seats in a row and a
side gangway with limited headroom. These were very unpopular with
the travelling public so, the Lodekka addressed this issue by a clever
design incorporating some ideas developed by the LGOC in the 1920s.
The Lodekka's running gear was kept low down and to one side in the chassis, thus
allowing the lower deck gangway to be lower. The use of a
patented drop-centre rear axle kept the gangway low between the wheels. This in turn led to an
overall reduction in height comparable with a standard 'low bridge' model.
The Lodekka, technically sophisticated for it's time, proved to
be an excellent vehicle.
Although never sold on the open market, many still exist either in
preservation or in use all around the world.

From the mid-1930s on Bristol buses have
been powered by diesel engines, either the ubiquitous 4, 5 or 6-cylinder
light-weight Gardner or a 6-cylinder power plant of Bristol's own
manufacture. Experiments with engine positioning in buses had been
carried out since the late 1920s, there being various arguments in favour
of not having the engine in front alongside the driver. The Bristol,
however, retained its engine in the traditional position until 1949 when
in line with trends in the rest of the industry Bristol introduced the LS
model with its engine mounted amidships. In 1962 the RE ('Rear
Engine') single-deck chassis was introduced and arguably became the UK's
most successful chassis of this type; starting life with a traditional
Bristol synchromesh gearbox it soon gained a semi-automatic epicyclic
gearbox manufactured under licence from Wilson. At last provincial
Bristol drivers acquired some of the luxury that London Transport drivers
had enjoyed for many years! In retrospect it seems this modification
was probably brought about as a result of a change in circumstances for
Bristol Commercial Vehicles. This occurred in 1965, when
Leyland took a substantial share in the company, Bristol was once again allowed to sell its vehicles on the open market
after being restricted to government-owned companies from 1950.

In 1966 the VR ('Vertical Rear') double
deck chassis was introduced and although suffering from some controversy
in its early years, the VR went on to become the last 'pure' Bristol
design manufactured by Bristol Commercial Vehicles. The VR was the
standard double-decker for the National Bus Company until the introduction
of the Leyland B45 Olympian (initially built at Bristol then later at
Workington) in 1981. The VR, Lodekka and RE were all
offered with Leyland diesel engines later in their production life.

On the following page are some views of the
different vehicles produced by Bristol over the years.